Conveyer apparatus and control systems therefor



Oct., 25, 1949. R. w. s|= AFFoRDl CONVEYER APPARATUS AND CONTROL SYSTEMSTHEREFOR Filed May 5, 1945 '2 Shere'ts-Sheet 1 oct. 25, 1949. R W,SPAFFORD 2,486,222

CONVEER APIPARATUS AND CONTROL SYSTEMS THEREFOR 'Filed May 5, 1945 zsheets-sheet 2 Patented Oct. 25, 1949 CONVEYER APPARATUS ANDCONTROLSYSTEMS THEREFOR Ralph W. Spaiiord, Fairfield, Iowa, -assignor lto TheLonden Machinery Company, Fairfield, Iowa, a corporation of AIowaApplication May 5, 1945, Serial No. 592,245

12 Claims.

This application relates to conveyor apparatus and .control systemstherefor, more particularly to conveyor control systems for effectingthe transfer of a conveyor moving on one trackway to another trackwayand it is an object of the invention to provide an improved conveyorcontrol system of the character indicated.

High speed production methods in modern industrial'plants make itparamount that material used in the manufacturing processes, the`partially completed product and the finished product be moved rapidlyfrom one point to another in order to have material available at alltimes and to remove the products to prevent congestion. High 'speedconveyor systems of the overhead monorail type are one `well known meansfor bringing about the rapid movements. The production of a completedarticle from raw materials is a complex process requiring numerousoperations performed in a specified order, the requirements of eachoperation frequently being so dierent in character that it must becarried on in a different part of the manufacturing plant. This ofcourse requires at least one conveyor trackway running from a mainconveyortrackway to the `point of operation and one returning from it tothe main trackway. Furthermore, the economical use of personnel requiresvthat the personnel work in a relatively small area thereby avoiding thespending vof considerable amounts of time moving from place to place.The .materials must therefore be brought to the point where each personis working and the resulting product must be moved away. Thisnecessitates at least one trackway extending from the main trackway toeach working point.

It thus becomes evident that conveyor systems of the character neededbecome exceedingly complex, requiring large numbers of trackways whichmust be joined together and integrated into a complete system in whichthe trackways extend in different directions from each other aredisplaced from each `otherand extend at different elevations, all ofwhich requires numerous vchanges of direction of movement of a conveyor.

To bring about the changes of direction on ,trackways at one elevationor the changes in elevation it is Well known to use a transfer ormovable trackway section registering with onel trackway to allow aconveyor Ato move onto the `transfer trackway which is thereafter moved.into registry with another trackway to permit the conveyor to move offof `the transfer track- -way and onto the-other trackway. In such ywellbeen hand controlled in that an operator must control the transfertrackway whenever a conveyor comes along. This causes the conveyorswtobe delayed, move 'slowly and leads to congestion. Accordingly, it is afurther object of the invention to provide an improved control systemfor a movable or transfer trackway in which `the transfer trackway isautomaticallyA controlled 'to move from one position'to another.

It is a further object of the invention to provide an improved automaticcontrol system for a transfer trackway responsive to the presence of aconveyor on the transfer trackway .for moving the transfer trackway fromone position to another.

It is a further object of the invention to provide an improved automaticlcontrol system for a transfer trackway controlled by a vconveyor movingon the trackway for moving the transfer trackway from one position toanother -with the conveyor on it and to return the transfer trackway toits first position after the conveyor has moved off of the transfertrackway.

In carrying out the invention in one form, a

convey-or system is provided-having a first trackway at one level, asecond 4trackway at anotherA level and an elevator trackway movablebetween.

two positions to come into registry with either of the trackways. Busbar means extend alongside .the respective trackways for supplying powerto a conveyor to. move a conveyor from the rst trackway onto theelevator trackway and from the elevator trackway onto the secondtrackway. To raise or lower the `elevator trackway between the twopositions, power means are provided along with control means. responsiveto the presence of 'the conveyor on the velevator trackway while inregistry with the first trackway for causing the power means to move theelevator trackway into registry with the second trackway. Additionalcontrol means are 'arranged on the second trackway so that when theconveyor moves from the elevator trackway and ontothe second trackwaythe power means are actuated toreturn the elevator into registry withthe first trackway.

For a more complete understanding of the invention, reference is made tothe accompanying drawings, in which:

Fig. 1 is a schematic view of conveyor apparatus and a control systemtherefor embodying the invention; and

Fig. .2 is a sectional .elevational view of a conknown installations thetransfer .trackways..have veyor elevator with the conveyor `'trackwaysex- 3 tending from it at different levels shown sche-1 matically in Fig.1.

Referring to Fig. 2 of the drawings, the invention is shown embodied ina monorail conveyorl system including a trackway II) at one elevation, atrackway II at a higher elevation, an elevator trackway I2 which ismovable from a position registering with the trackway I to a position(shown dotted) registering with the trackway I I and a conveyor I3movable on the respective trackways. The trackways I0 and II aresuitably supported by means including the beam members I4 and I5attached, respectively, at their inner ends to the horizontal beams I6and I'I which in turn are attached, respectively, to the verticalcolumns I8 and I9 of the elevator framework 20.

The elevator framework 2t guides and supports an elevator section orlift section 2l in its vertical movements and includes four verticalcolumns arranged at the corners of a square or rectangle of which thevertical columns IB and I9, as shown, form one side extending parallelto the beams I4 and I5. The vertical columns I8 and I9 are supported onfoundation members 22 and 22a, extend to the necessary height and arerigidly joined at their upper ends by the beam member 23. Also rigidlyjoined at one end to the vertical columns I8 and I9 extending at rightangles to the beam member 23 are the beam members 24 and 25,respectively, which are rigidly joined at their other ends to thevertical columns forming the other side of` the square or rectangle tocomplete the elevator framework. The beam members I6 and I'I are rigidlyattached to and extend between the vertical columns on the sides of thelsquare or rectangle corresponding, respectively, to the verticalcolumns I8 and I9 and the beam members I4 and I5 are centrally supportedbetween the vertical columns on each side of the rectangle or square bythe beam members i6 and I'I, respectively. The various beams areattached to each other by means of rivets, welding or any other wellknown means.

The elevator section or lift 2| including the elevator trackway I2 isarranged within the elevator framework 2B and has sliding members alsoarranged at the four corners of a square Aor rectangle to slidablyengage, respectively, each `of the vertical columns. In the drawing onlythe lslide members 26 and 2l associated, respectively, with the verticalcolumns I8 and I9 are shown. Extending between the slide members on thesides of the elevator section 21| corresponding to the slide members 26and 27 are the beam mem- -bers 28 and 2K9 which support a beam member 30centrally between them. The slide members and the several beam membersform a rigid structure which is guided in its vertical movements by thevertical columns. Mounted on the beam member 30 are the vertical hangers3|, 3Ia and 3Ib which support the elevator trackway I2 so that in theposition shown the trackways IU and vI2 are in registry and in theraised position (shown dotted) the trackways I2 and II are in registry.

At the upper end of the elevator framework 20 a motor 32 for raising andlowering the elevator section ZI is supported by means shown as thechannel members 33 and 34 attached at one end to the beam member 23 byany well known means such as welding and similarly attached at the otherend to a beam member correspond- Ving to the beam member 23. The motor32 drives a shaft 35 through a gear box (not shown) and drums 36 and 31are attached, respectively, to the ends of the shaft, the shaft beingsupported by the vertical hangers 38 and 39. Wrapped around the drums 35and 3'I are cables 40 and 4I, respectively, which cables extendrespectively around pulleys 42 and 43 attached to the beam 3B, the endsof the cables being attached through the U bolts 44- and 45 to the anglemembers 46 and 47 which are rigid with the beam members 24 and 25,respectively. Operating the motor 3'2 in one direction turns the shaft35 and consequently the drums 3i) and 3l thereby wrapping the cables and4I around the drums and by virtue of the structure described theelevator section 2| is raised to bring the elevator trackway I2 intoregistry with the trackway II. Rotating the motor in the other directionlowers the elevator section 2l to bring the elevator trackway I2 intoregistry with the trackway IU. Limit switches 48 and 49 are stationarilymounted on the elevator framework 20 and are actuated by the elevatorsection 2I to control the position of the trackway I2. The circuits tothe limit switch contacts and the circuits to control the motoroperation will be described subsequently in this specication.

The conveyor I3 is shown somewhat schematically as including trolleywheels 50 and 5I adapted to run on the monorail trackways, the trolleywheels 5D and 5I supporting the conveyor; The conveyor also includes adriving motor 52 and the current collectors or trolleys 53 and 53a (Fig.l), each of the current collectors 53 and 53a comprising a pair ofspaced wheels adapted to engage the bus bars extending alongside thevarious trackways. Power is supplied to the driving motor 52 from thebus bars through the current collectors, the bus bars being insulatedfrom the trackways and supported in proper relation thereto by wellknown means not illustrated.

The conveyor apparatus shown in Fig. 2 and ldescribed with referencethereto is illustrated schematically along with the control system forthe conveyor and the elevator section in Fig. 1, corresponding elementsbeing designated by the same reference characters.

Extending alongside of the lower trackway II) are the bus bar sections54 and 54a insulated from the trackway I0 and suitably supported inconnection therewith to receive the trolleys 53 and 53a of the conveyorI3. The bus bar sections 54 and 54a are insulated at one end by theinsulators 51 and 51a from the bus bars 58 and 58a, extending alongsidethe remaining trackway and are provided at their other ends with theinsulators 59 and 60. The bus bars 54 and 54a, combined with the portionof the trackway I0 corresponding thereto, form a dead section so that aconveyor moving on the trackway I0 can move off of the trackway I3toward the elevator trackway I2 only when the elevator trackway I2 is inregistry with the trackway I0.

The elevator section 2l in addition to the elevator trackway I2 includesthe bus bars 55 and 55a extending alongside the trackway I2, limitswitches to control the supply of power to the bus bars, controlcircuits, and sliding contacts to coact with stationary sliding contactsto connect the various circuits to external circuits which will be morecompletely described, the bus bars and 55a having insulators BI and E2arranged at one end and insulators 63 and 64 arranged at the other end.In the lowered position where the trackway I2 registers with thetrackway I0 the 4 bus bars 55 and 55a are prevented from contacteasshowmsoxthat the insulators: do. notcontactV eachzother.'` To. stoptheconveyor: after it has moved; onto: the elevator trackway |:2 the,busbar` 55vis interrupted. by accntrol section. which includesithetinsulators 65 and 66. separated byv a, conductor 61. The operation@ofthe control sec:- tionwill be: explained subsequently. To supplypcwerfto thebus'bars 55,' and*` 55a; when the, elevator, section is inthe loweredposition, sliding contacts-68" and 69 are provided on theelevator section which cooperate with sliding contacts and which are.stationarily mounted on. the elevator: framework. 2.0. To. conduct thepower from thebus bars55 and 55a to the bus bars: 54 and'. 54a: thesliding' contacts 12 and 13 are pro.- vi'ded on the. elevator section 2|to coact with corresponding sliding contacts 14 and 15, alsostationarily mounted on the elevator framework 20.

The control circuits on the elevator section 2| which are operative whenthe elevator section is in the? lowered position include the slidingcontacts 16,11 and 18 mounted on the elevator sectiontc coact with thecorresponding sliding contacts..'|9, 80 andv 8|,.respectively, mountedon the elevator framework: 20. The sliding contacts 82 andl83 are alsomounted on the elevator section 2| but coact with the sliding contacts84 and 85, respectively, only' when the elevator section is in theraised position, the sliding contacts 84 and 85I being' stationarilymounted on the elevator framework; To supply power to the bus bars 55and 55a when theelevator section 2| is in the raised positicnthe slidingcontacts 85 and 81 are mounted on the elevator framework and coact withthe sliding contacts' 12 and 13 on the elevator section.

Similarly to the trackway |0 the trackway has bus bar sections 56 and56a associated therewith. The bus bar sections are insulated at one endby the insulators 88 and 89 from the bars' 92 and 92a which extend alongthe remaining por-v tion of the trackway and have insulators 90 and 9|arranged at their other ends so that the bus bars 55 and 55a do' not'contact directly the bus bars 56 and 56a when the elevator section is'in the raised position and the busbars are physically separated by a gapas shown. The bus bars 56r and 56a, along with the portion of thetrackway corresponding thereto, form a dead section which is unenergizedunless the elevator trackway |2'is in registry with the trackway (theelevator section is in the raised position). Tosupply power to the busbar sections 56 and 56a the elevator framework 20 has the stationarysliding contacts |60 and |'6| mounted on it to coact with the slidingcontacts 68 and 69, respectively, on the elevator section 2|. Formingpart of the bus bar 92 and arranged in a position beyondthe insulator88, is a control section which includes the insulators 93 and 94`separated by a: conductor 95, the conductor 95 being adapted to' becontactedbythetrolley collector 53'which eriergizesa circuit to bedescribed' for lowering: the. trackway I2' from registryl with thetrack-y way into registry with the trackway |0. For amore completedescription of the control sections, reference is made to the applicantscopending application Serial No. 523,635, filed February 24, 1944, andentitled Crane construction and apparatus.

Limit switches 96 and 91 Y are mounted on the elevator: section. 2li:andI are. adapted. to bei: actu.-l ated by suitableabutments,indicatedizby-therbrcke emarrows 98 and 99, on the elevator'.framework; 20 when the elevator section is in either the low.-

, ered or raised; positions to control relays. (as will be describedl.to energize thev appropriate.' bus; bars only: wherrth'e.;` elevatortrackway |22 isV in: registrywithftheftrackway |0or The.: motor. 32.is,V ofY a. type well known. ini thez electrical, artr` and includes; anarmature |001 andi a field |0 which. may` be. excited. fromv any.lsuit.-w abley source: of. current; for example, the` samesources-asisfusedzto supply power: tozthe.` bus bars'. While; a directcurrent. motor.' is' shown it iszcbviousithat alternating current motorsmay be used and iti. will also be'. clear to those skilled in. this.:artthataalternatingf current which maybe single; or multi.: phase may.'be: used. to supply' theA pro` pulsioni motor andiother apparatus.y

Power is supplied? to: the various busybars for.rr supplyingpowerto theconveyor motor 52- in order:Y to: move the" conveyor.` to theV variouscontrol cir-.- cuits and relays as well asto the raising and lowering:motor 32rifrom a source of power designated.`v by the charactersvLiandfLa.

The control of. the elevator.l section 2|- and the conveyor inconnectiontherewith is entirelyrauto-y m'aticand has four phases; thelmovement-'ofthex conveyor onto the elevator trackway; the raising:v of.'the* elevator trackway; the movement of the?` conveyor off ofi theelevatorl trackway and low-- ering of the elevator'trackwaytoritscriginalipo-f sition. The description' of the control system andan understanding offthe operation of' the conveyor system andits controlmay best be set forth by.v considering the aspects-ofv the system ineach. offthe four phases indicated above as--aconveyor moves' over thetrackways.

In the rlrst` phase of" operation the elevator trackway |.2l is invitslowered position in registry' with1the trackway I0 and'assuming thatrtheconveyor |3-v has'not approached that pcrtionof the= trackway |'0ycorresponding to the bus bars 54 and54'a, thef'ollowing will be thecondition of the: various circuits. The contacts 48a of the limit switch48 are closed and the contacts 48h are-open. The contacts of the limitswitch- 49 are closed energizing-the coil |02 of the relay |03 to openythe contactsr |'04througha circuit extending from Lr through limitswitch contacts 49, conductor |i05-,acoil |02? tol L2; The relay |03 isof themechanically latched type having an overcenter mechanismV |06 andhas the opening coil |02 and a.v closing coil |01. The overcenter device|06` maintainsthe contacts |04 4in either position until the coilfortheother position is energized. Since' the contacts |04'l are open therelay coil |08 isk unenergized andthe contacts |09 and' ||0 are open.Consequently the motor armatureI |00' isA unenergi'zedV andi; therefore,the motor is station*- ary.; The= contacts of? limit switch 96 areclosed by the abutment 98 which completes a circuit extending from L2through the sliding contacts 8| and 18, contacts of limit switch 96,conductor |'|.|i, sliding: contacts 11. and' 80, conductor |'2, relaycoil i3', conductor ||4, normally closed contacts |,I5of relay ||6 andconductor ||1 to L1. This circuit energizesthe relay coil ||3 whichcloses' the contacts ||8 and ||9 and thereby energizes'the bus bars 55and 55a through circuitsr extending from L1 and L2, relay contacts ||8and 9, conductors |20 and |2'|, sliding contacts 10, 68 and-1|, 69 andconductors |22 and |23 tol bus bars 55T- and 55a. The bus bars 54 and54a are; thereby energized throughy circuits extending-1 from bus bars55 and 55a through conductors- |24 and |25, sliding contacts 12, 14 and13, 15 and conductors |26 and |21 to the :bus bars 54 and It is seen,therefore, that the bus bars 54 and 54a are energized and the conveyorI3 moving along the trackway I will move onto the elevator trackway I2,power being supplied to the conveyor through the trolleys 53 and 53a incontact with the bus bars 54 and 54a, respectively. After the conveyorhas moved completely onto the elevator trackway I2, the front wheel ofthe current collector 53 contacts the control section conductor 61 whilethe rear wheel thereof remains in contact with the bus bar 54 therebyenergizing the relay coil |28 of the relay ||6 through a circuitextending from the source L1, bus bar 55, collector 53, control sectionconductor 61, conductor |29, sliding contacts 16, 19, conductor |30 andrelay coil |29 to L2. Energizing the coil |28 causes the relay I6 toopen its contacts ||5 thereby interrupting the current to the relay coilI|3 and consequently opening the contacts ||8 and |'I9 which disconnectsthe bus bars 55 and 55a from the source L1 and L2. Since the power isnow removed from bus bars 55 and 55a, the conveyor stops and since thebus bars 54 and 54a are connected to the bus bars 55 and 55a these busbars are also now deenergized and, therefore, any other conveyorapproaching the trackway I2 will be stalled on the dead sectioncorresponding to the bus bars 54 and 54a.

The rst phase of the operation is now complete and the second phasebegins.

Similarly to relay |03 the relay ||6 is a mechanically latched relay andis maintained by the overcenter device |3| in whatever position it isactuated to by either of its coils |28 and |32 until a further actuatingimpulse is received to change the position. When the relay ||6 waspicked up by energizing the coil |28 through the previously describedcircuit the contacts |33 also closed. Closing the contacts |33 energizesthe coil |34 through the circuit extending from L1, closed limit switchcontacts 48a, conductor |35, closed contacts |33, conductor |36 and coil|34 to L2. Energizing the coil |34 closes the contacts |31 and |38 andthereby energizes the motor armature |80 through a circuit extendingfrom L1 and L2, contacts |38 and |31, conductors |39 and |40 andconductors |4| and |42, the motor thereupon operating through mechanismillustrated in Fig. 2 to raise the elevator trackway |,2 with theconveyor I3 on it into registration with the trackway II. This movementof the elevator section '2| opens the contacts of the limit switch 49and deenergizes the coil |02. The upward movement of the elevatorsection 2| also opens the limit switch contacts 96 which produces nocontrol eiect sincethese limit switch contacts control the energizationof the bus bars 55 and 55a which energization has already been removed.

After the elevator section 2| has reached its position where thetrackway I2 is in registry with the trackway (shown dotted) the limitswitch contacts 48a are opened and the limit switch contacts 48h areclosed. Opening the contacts 48a interrupts the previously describedcircuit to the relay coil |34 thereby opening the contacts |31 and |38to deenergize the motor armature |00 which thereby :brings the elevatorsection 2| to a rest, the adjustment of the limit switch 48 being suchthat the trackways I2 and are in registry. Closing the limit switchcontacts 48b contacts |04 to L1.

energizes the coil |32 of the relay I I6 through a circuit extendingfrom L1, contacts 48h, conductor |53 and coil |32 to Lz. Energizing coil|32 trips the overcenter mechanism |3| which closes the contacts ||5 andopens the contacts |33 thereby conditioning the relay coil ||3 so thatit can be energized when the elevator section is in the loweredposition. This completes the second phase of the operation.

The limit switch contacts 91 which are open in the lowered position ofthe elevator trackway are closed in the raised position of the elevatorsection by a stationary projection 99 thereby energizing the relay coil|4|a through a circuit extending from L1, conductor |42a, relay coilI4Ia, sliding contacts 85, 83, conductor |43, limit switch contacts 91and sliding contacts 02, 84 to L2. Energizing the coil I4|a closes therelay contacts |44 and |45 thereby energizing the bus bars 55 and 55athrough circuits extending from L1 and L2, contacts |44 and |45,conductors |46 and |41, sliding contacts 86, 12 and 81, 13, conductors|24 and |25 to the bus bars 55 and 55a. The conveyor motor 52 is thusenergized through 'the trolley 53 and the conveyor moves ofi of thetrackway I2 onto the trackway The bus bars 56 and 56a are energized fromthe bus bars 55 and 55a through circuits extending from the bus bars 55and 55a, conductors |22 and |23, sliding contacts 88, |50 and 69, |6|and conductors |55 and |56 to the bus bars 56 and 56a.' The third phaseof the operation is now completed.

The conveyor continues to move over the trackway I I and the currentcollecting apparatus contacts the bus bars 92 and 92a until the trolleycollector 53 contacts the control section conductor 95 which energizesthe relay coil |01 through a circuit extending from L1, bus bar 92,trolley collector 53, control section conductor 95, conductor |48 andcoil |01 to L2. Energizing the coil |01 closes contacts |04 of themechanically latched relay |03 and thereby energizes the relay coil |98through the circuit extending from Lz, conductor |49, coil |08,conductor |50 and Energizing the coil |08 closes the contacts |09 and||0 thereby energizing the motor armature |00 through circuits extendingfrom Lz and L1, contacts |09 and |I0, conductors |5| and |52 andconductors |4| and |42 to the motor armature causing the motor to rotatein the reverse direction to lower the elevator trackway |2 from registrywith trackway to registry with trackway I0.

As the elevator section 2| moves downward, the limit switch contacts 91are opened to deenergize the coil |4|a which opens the contacts |44 and|45 and thereby removes the power from the bus bars 55 and 55a, as wellas the bus bars 56 and 56a. section 2| also closes the limit switchcontacts 46a and opens the limit switch contacts 48h therebydeenergizing the coil |32.

When the elevator section reaches its lowered position the limit switchcontacts 49 are closedv thereby energizing the relay coil |02 to tripthe overcenter mechanism |06 and open the relay contacts |04. Openingthe contacts |04 deenergizes the coil |08 which in turn opens thecontacts |09 and I I0 to deenergize the motor armature |00 therebystopping the conveyor movement, the limit switch contacts 49 being soadjusted that they' The lowering movement of the elevator the relaycontacts H8 and H9 for supply-lng 4,'QOWer to the bus bars 55 and 55a,and '54 and 54a and 'the system is ready for another cycle of operation.

AIt 'is tobe noted .that the bus vbars 56 and 56a are insulated from thevbus 'bars -92 and 92a and `are -energized only .when the elevatorsection is in 'the raised position and thus conveyors are prevented'from moving toward the elevator section '21 on the trackway il. Inorder to prevent the interruption of power flow from the bus lbars Vtovthe motor 52 when .the trolley 53 strikes the control section, thespacing of the trolley wheels suiciently long so that the trolley canspan over the control section and contact the bus bar on each side.

While aparticular embodiment of the invention has been-shown it will beunderstood, of course, that vthe 'invention is not :limited theretosince `many modifications maybe made, and it is, therelfore,contemplated by the appended claims to 'cover any such modications ascome within the true vspirit and scope ofthe invention.

Having Athus ,described the invention, what is Aclaimed Aand desired 'tobe secured by Letters Patent is:

1. A uconveyor system comprising an elevator, a rst trackway at onelevel, a second trackway .atl'another level, aitrackway carried by saidele- 'vatorbetween two'positions to come into registry with said rst orsecond trackways, power means for raising and Vlowering :said elevatortrackway `betweensaid two positions, bus bar means individual `to Yeachof said trackways and extending therealong to 'supply vpower to a`conveyor for `moving said conveyor along said'trackways, powersupplymeans kfor said bus bar means, means controlled'by'said elevatorfor connecting said power vsupply to the bus bar means individual tosaid elevator trackway and the one of said first or 'second trackwaysrespectively only when said `elevator trackway Vis in Aregistry withlsaid one of said rst'or'second trackways, means responsive to'thepresence of a conveyor on said elevator trackwaywhile in registry withsaid first track- A-wayat one'level 'for-controlling said elevatorcontrolled means `to deenergize the bus bar means jindividual to saidelevator traclcway whereby la -lconveyor will "be stopped on saidelevator track- '-way, said responsive means also being eiective"tocontrol saidpower-means to move said elevator A'trackway intoregistrylwith said second traclcway at another level and additional controlmeans responsivelto the passage of a conveyor from said "elevatorftrackwayfand over said second track- Way for causing said power meansto move said "elevator trackway into registry with said first 'trackwayl r2. Aconveyorsystem comprising an elevator, a "rst `trackway atlone'level, a second trackway at anotherilevel, a trackway carried bysaid elevator 'between ltwo positions to come into registry withfsaidfirst -or second trackways, power means for Araising vand loweringlsaid elevator trackway bey@tween lsaidtwo positions, bus bar meansindividual 'to each'ofsaid trackways and extending therealong 'tosupplypower to a conveyor for moving lsaid conveyor along said trackways,power sup'- plymeans "iior said bus bar means, means conltrolledby saidelevatorforsconnecting said power Yfsuprply to the bus bar meansindividual to said -elevator trackway and said-first or second track-=waysforily `when said velevatcr'tra'ckway is inv regf-is'try lwith:said first or second trackways, means =respon`sive lto :thepresenceio'f-a conveyoron Said elevator trackway while in registry withSaid rst trackway at one level for controlling Said elevator controlledmeans to deenergize the bus bar means individual to said elevatortrackway whereby a, conveyor will be stopped on said elevator trackway,said responsive means also being eiective to control said power means tomove said elevator trackway toward said second trackway, means fordeenergizing said piower means when said elevator trackway comes intoregistry with said second trackway at said other level, additionalcontrol means responsive to the pas,- sage ci a conveyor from saidelevator trackway and lover said second trackway `for causing said powermeans to move said elevator trackway to.- ward said first trackway, Aandmeans for deenergizing said power means when said elevator track,- waycomes into 'registry -with said first trackway at said one level.

3. A conveyor system comprising an elevator, a rst trackway at onelevel, a second trackway at another level, a trackway carried by saidelevator between two positions to ycome into registry with said rst orsecond trackways, power means for raising and lowering said velevatortrackway vbe- .tween said two positions, bus bar means insulated fromeach other and individual to each of said trackways to supply power toaconveyor for moving said conveyor along said trackways, power supplymeans rior said bus bar means, means controlled by said elevator forconnecting said power supply to the bus bar means 'individualto saidelevator trackway and -to said -rst trackway only when said elevatortrackway is in registry with said first trackway, vmeans responsive rtoAthe presence of a conveyor on said elevator trackway while in registrylwith said rst trackway at one level yfor controlling said elevatorcontrolled Imeans to deenergize the bus bar means individual to saideleva-tor -trackway and said first trackway whereby a conveyor will bestopped on said elevator trackway, said responsive means .azlsobeingeffective to control said power means to Amove said elevator trackwaytoward said second trackw-ay, means for deenergizing said power #meanswhen said elevator itrackway comes into ,registry with said secondtrackway at said other level, means controlled by said elevator forconnecting rsaid power supply to rthe bus "bar means :individual to saidelevator trackwjayand-said second `,traickway only when said elevatortrackway is `in registry with said second trackway, 4additional controlmeans ,responsive to the passage ,of a conveyor from said elevato-rtrackway andover Said second trackway for ,causing `said power means tomoyesaid elevatortrackwavtoward said -rst track-Way, and means fordeeneraizins .said newer means when .said elevator .trackway .comes intoregistry with said first tracliway at said one level.

4. A travelling conveyorsystem comprising an elevator, a rst'trackwaysection carried thereby, 'bus bar means including an insulated first bus"bar section extending alongside said A-trackway section and-.carried bysaid elevator, an entrance second 'trackway section on one level withwhich said -rst-trackway is-alignable, bus 'barmeansincluding aninsulatedfsecond leus bar section eX- "tending alongside said Ysecond--trackway section, an `exit third -trackway section on a differentlevel with which said first trackway section is alignable, busbar meansincluding-an insulated-third bus bar-section extending alongside saidthird itraclrway section, power hoist means for controlling the raisingand lowering of said elevator,

an electric power supply for said bus bars, a conveyor designed totravel from said second trackway onto said first trackway when thesetrackways are in alignment and from said first trackway-onto said thirdtrackway when these trackways are in alignment, an electric motorcarried by said conveyor for propelling it, collector means vcarried bysaid conveyor for successively engaging 1 said three bus bar sections,means for automatically electrically connecting said first and secondbus bar sections with said power supply when said first trackway is inalignment with said second trackway to enable the conveyor to move fromthe second trackway onto the first trackway, means 4controlled by saidconveyor for automatically electrically disconnecting said rst andsecond bus bar secti'ons from said power supply and energizing the hoistmeans to move the elevator from said first level to said second levelwhen the conveyor has travelled onto the rst trackway, means lcontrolledby the elevator for automatically electrically connecting said first busbar section with the power supply and for stopping the power hoist meanswhen the second level is reached to enable the conveyor to move fromsaid first trackway onto said third trackway and for conditioning thepower supply circuit to energize the first bus bar section and thesecond bus bar section when the elevator shall be returned to said firstlevel, and means controlled by the conveyor for causing the l'roistmeans to move the elevator from said -said trackways, and meansindependent of elevator trackway movement responsive to the movement ofa conveyor onto said elevator trackway at one of its positions foreffecting deenergization of said conveyor propulsion motor, said`responsive means also being effective when said conveyor is on saidelevator trackway for automatically energizing said power means formoving said elevator trackway to the other of its positions.

6. A conveyor system comprising an elevator, a first trackway at onelevel, a second trackway at another level, a trackway carried by saidelevator between two positions to come into registry with said first orsecond trackways, power means for raising and lowering said elevatortrackway between said two positions, bus bar means individual to each ofsaid trackways and extending therealong to supply power to thepropulsion motor of a conveyor for moving thereof along said trackways,and means independent of elevator trackway movement responsive to themovement of a conveyor onto said elevator trackway at one of itspositions for effecting deenergization of said bus bar means individualtosaid elevator trackway thereby to stop said conveyor movement, saidresponsive means also being effective when said conveyor is on saidelevator trackway for automatically energizing said power 12 means formoving said elevator trackway to the other of its positions.

7. A conveyor system comprising an elevator, a first trackway at onelevel, a second trackway at another level, a trackway carried by saidele-- vator between two positions to come into registry' with said firstor second trackways, power means for raising and lowering said elevatortrackway between said two positions, bus bar means individual to each oisaid trackways and extending therealong to supply power to thepropulsion motor of a conveyor for moving thereof along said tnackways,and means independent of elevator trackway movement responsive to themovement j of a conveyor onto said elevator trackway at one of itspositions for effecting de-energizationof said bus bar means individualto said elevator trackway thereby to stop said conveyor movement, saidresponsive means also being effective when said conveyor is on saidelevator trackway for automatically energizing said power means to movesaid elevator trackway to the other of its positions, and additionalcontrol means responsive to the pass-age of the conveyor fram saidelevator trackway `and over the trackway at said other position forcausing said power means to move said elevator trackway back into saidone of its positions.

8. A conveyor system comprising a first trackway, a second trackwaydisplaced from said first trackway, an intermediate trackway movablebetween rst and second positions to come into registry with said rst orsecond trackways respectively, power means for moving said intermediatetrackway between said positions, bus bar means individual to each ofsaid trackways and extending therealong to supply power to thepropulsion motor of a conveyor for moving said conveyor along saidtrackways, power supply means for said bus bars, means independent ofelevator trackway movement responsive to the movement of a conveyor ontosaid intermediate trackway at the first of its positions for effectingdisconnection of the power supply from said intermediate trackway busbars, said responsive means also being effective when said conveyor ison said intermediate trackway for automatically effecting energizationof said power means to move said intermediate trackway to the second yofits positions, means responsive to the movement of said intermediatetrackway into registry with said second trackway at said second positionfor automatically connecting said power supply to said intermediatetrackway bus bars thereby energizing said propulsion motor to move theconveyor off of said intermediate trackway, and means associated withsaid second trackway responsive to the passage of a conveyor therealongfrom said intermediate trackway for causing said power means to movesaid intermediate trackway back into registry with said first trackway.

9. A conveyor system comprising a first trackway, a second trackwaydisplaced therefrom, an intermediate trackway movable between first andsecond positions to come into registry with said rst or second trackwaysrespectively, power means for moving said intermediate trackway betweensaid positions, bus bar means individual to each of said trackways andextending therealong to supply power to the propulsion motor of aconveyor for moving said conveyor along said trackways, power supplymeans for said bus, bars, means controlled by said intermediate trackwayfor connecting said power supply to the bus bar means individual to saidintermediate trackway and the rst of said first or second trackwaysrespectively only when said intermediate trackway is in registry withsaid one of Said rst or second trackways, means responsive to themovement of a conveyor onto said intermediate trackway while in registryWith said rst trackway for controlling said intermediate track- Waycontrolled means to de-energize the bus bar means individual to saidintermediate trackway whereby a conveyor will be stopped on saidintermediate trackway, said responsive means also being eiective tocontrol said power means to move said intermediate trackway intoregistry with said second trackway, and additional control meansassociated with said second trackway and responsive to the passage of aconveyor therealong from said intermediate trackway for causing saidpower means to move said intermediate trackway into registry with saidfirst trackway.

10. In a conveyor system, apparatus for controlling movement of aconveyor carrier from one position to another comprising, means forsupplying power, rst contact means operated by said carrier in one ofits positions for controlling said power supply means to supply power tosaid carrier, second contact means controlled by a conveyor running ontosaid carrier and independent of carrier movement for controlling saidpower supply means -to remove power from said carrier, and third contactmeans also controlled by a conveyor running onto said carrier foreiecting movement of a carrier with a conveyor thereon from one positionto another position.

1l. In a conveyor system, apparatus for controlling movement of aconveyor carrier from one position to another comprising, a bus bar onsaid carrier adapted to be contacted by conveyor collectors, means forsupplying power to said bus bar, an insulated control conductorassociated with said bus bar, rst contact means operated by said carrierin one of its positions for controlling said power supply means tosupply power to said bus bar, second contact means operated by aconveyor collector contacting said control conductor for controllingsaid power supply means to remove power from said bus bar, and thirdcontact means also controlled by said conveyor collector contacting saidcontrol conductor for eiecting movement of a carrier from one positionto another.

12. In a conveyor system, apparatus for controlling movement of aconveyor carrier from one position to another comprising, a bus bar onsaid carrier, a bus bar preceding said carrier at one position andadapted to come into registry with said carrier bus bar, a bus barfollowing said Carrier at another position and adapted to come intoregistry with said carrier bus bar, said conveyor including a collectoradapted to run on said -bus bar, said carrier bus bar having aninsulated control conductor associated therewith, said following bus barhaving an insulated control conductor associated therewith, rst meansfor supplying power to said carrier bus bar, rst contact means operatedby said carrier at said one position for controlling said rst powersupply means to supply power to said carrier bus bar, second contactmeans operated by said conveyor collector contacting said carrier busbar control conductor for controlling said first power supply means toremove power from said carrier bus bar, third contact means alsocontrolled by said conveyor collector contacting said carrier bus barcontrol conductor for effecting movement of said carrier from said oneposition to said other position, a second power supply means, contactmeans controlled by said carrier in said other position for controllingsaid second power supply means to supply power to said carrier bus bar,and contact means controlled by a conveyor collector contacting saidfollowing bus bar control conductor for effecting movement of saidcarrier from said other position to said one position.

RALPH W. SPAFFORD.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

